Botan::TLS::Extensions Class Reference

#include <tls_extensions.h>

Public Member Functions
void	add (Extension *extn)
void	add (std::unique_ptr< Extension > extn)
const std::vector< std::unique_ptr< Extension > > &	all () const
bool	contains_implemented_extensions_other_than (const std::set< Extension_Code > &allowed_extensions) const
bool	contains_other_than (const std::set< Extension_Code > &allowed_extensions, const bool allow_unknown_extensions=false) const
void	deserialize (TLS_Data_Reader &reader, const Connection_Side from, const Handshake_Type message_type)
std::set< Extension_Code >	extension_types () const
	Extensions ()=default
	Extensions (Extensions &&)=default
	Extensions (TLS_Data_Reader &reader, Connection_Side side, Handshake_Type message_type)
template<typename T >
T *	get () const
Extension *	get (Extension_Code type) const
template<typename T >
bool	has () const
bool	has (Extension_Code type) const
Extensions &	operator= (Extensions &&)=default
bool	remove_extension (Extension_Code type)
std::vector< uint8_t >	serialize (Connection_Side whoami) const
size_t	size () const
template<typename T >
decltype(auto)	take ()
std::unique_ptr< Extension >	take (Extension_Code type)

Detailed Description

Represents a block of extensions in a hello message

Definition at line 835 of file tls_extensions.h.

Constructor & Destructor Documentation

Extensions() [1/3]

Botan::TLS::Extensions::Extensions ( )

default

Extensions() [2/3]

Botan::TLS::Extensions::Extensions ( Extensions &&  )

default

Extensions() [3/3]

Botan::TLS::Extensions::Extensions ( TLS_Data_Reader &  reader, Connection_Side  side, Handshake_Type  message_type  )

inline

Definition at line 949 of file tls_extensions.h.

         {
         deserialize(reader, side, message_type);
         }

Member Function Documentation

add() [1/2]

void Botan::TLS::Extensions::add ( Extension *  extn )

inline

Definition at line 869 of file tls_extensions.h.

         {
         add(std::unique_ptr<Extension>(extn));
         }

add() [2/2]

void Botan::TLS::Extensions::add

(

std::unique_ptr< Extension >

extn

)

Definition at line 103 of file tls_extensions.cpp.

   {
   if (has(extn->type()))
      {
      throw Invalid_Argument("cannot add the same extension twice: " +
                             std::to_string(static_cast<uint16_t>(extn->type())));
      }
 
   m_extensions.emplace_back(extn.release());
   }

References has().

Referenced by deserialize().

all()

const std::vector< std::unique_ptr< Extension > > & Botan::TLS::Extensions::all ( ) const

inline

Definition at line 840 of file tls_extensions.h.

         {
         return m_extensions;
         }

contains_implemented_extensions_other_than()

bool Botan::TLS::Extensions::contains_implemented_extensions_other_than ( const std::set< Extension_Code > &  allowed_extensions ) const

inline

Parameters

allowed_extensions

extension types that are allowed

Returns

true if this contains any extensions implemented by Botan that are not contained in allowed_extensions.

Definition at line 903 of file tls_extensions.h.

         {
         return contains_other_than(allowed_extensions, true);
         }

contains_other_than()

bool Botan::TLS::Extensions::contains_other_than	(	const std::set< Extension_Code > &	allowed_extensions,
		const bool	allow_unknown_extensions = false
	)		const

Parameters

allowed_extensions	extension types that are allowed
allow_unknown_extensions	if true, ignores unrecognized extensions

Returns

true if this contains any extensions that are not contained in allowed_extensions.

Definition at line 148 of file tls_extensions.cpp.

   {
   const auto found = extension_types();
 
   std::vector<Extension_Code> diff;
   std::set_difference(found.cbegin(), found.end(),
                       allowed_extensions.cbegin(), allowed_extensions.cend(),
                       std::back_inserter(diff));
 
   if(allow_unknown_extensions)
      {
      // Go through the found unexpected extensions whether any of those
      // is known to this TLS implementation.
      const auto itr = std::find_if(diff.cbegin(), diff.cend(),
                                    [this](const auto ext_type)
         {
         const auto ext = get(ext_type);
         return ext && ext->is_implemented();
         });
 
      // ... if yes, `contains_other_than` is true
      return itr != diff.cend();
      }
 
   return !diff.empty();
   }

References extension_types().

deserialize()

void Botan::TLS::Extensions::deserialize	(	TLS_Data_Reader &	reader,
		const Connection_Side	from,
		const Handshake_Type	message_type
	)

Definition at line 114 of file tls_extensions.cpp.

   {
   if(reader.has_remaining())
      {
      const uint16_t all_extn_size = reader.get_uint16_t();
 
      if(reader.remaining_bytes() != all_extn_size)
         throw Decoding_Error("Bad extension size");
 
      while(reader.has_remaining())
         {
         const uint16_t extension_code = reader.get_uint16_t();
         const uint16_t extension_size = reader.get_uint16_t();
 
         const auto type = static_cast<Extension_Code>(extension_code);
 
         if(this->has(type))
            {
            throw TLS_Exception(TLS::Alert::DecodeError,
                                "Peer sent duplicated extensions");
            }
 
         // TODO offer a function on reader that returns a byte range as a reference
         // to avoid this copy of the extension data
         const std::vector<uint8_t> extn_data = reader.get_fixed<uint8_t>(extension_size);
         TLS_Data_Reader extn_reader("Extension", extn_data);
         this->add(make_extension(extn_reader, type, from, message_type));
         extn_reader.assert_done();
         }
      }
   }

References add(), Botan::TLS::TLS_Data_Reader::get_fixed(), Botan::TLS::TLS_Data_Reader::get_uint16_t(), has(), Botan::TLS::TLS_Data_Reader::has_remaining(), and Botan::TLS::TLS_Data_Reader::remaining_bytes().

extension_types()

std::set< Extension_Code > Botan::TLS::Extensions::extension_types

(

)

const

Definition at line 227 of file tls_extensions.cpp.

   {
   std::set<Extension_Code> offers;
   std::transform(m_extensions.cbegin(), m_extensions.cend(),
                  std::inserter(offers, offers.begin()), [] (const auto &ext) {
                     return ext->type();
                  });
   return offers;
   }

Referenced by contains_other_than().

get() [1/2]

template<typename T >

T * Botan::TLS::Extensions::get ( ) const

inline

Definition at line 846 of file tls_extensions.h.

         {
         return dynamic_cast<T*>(get(T::static_type()));
         }

References T.

get() [2/2]

Extension * Botan::TLS::Extensions::get ( Extension_Code  type ) const

inline

Definition at line 874 of file tls_extensions.h.

         {
         const auto i = std::find_if(m_extensions.cbegin(), m_extensions.cend(),
                                     [type](const auto &ext) {
                                        return ext->type() == type;
                                     });
 
         return (i != m_extensions.end()) ? i->get() : nullptr;
         }

has() [1/2]

template<typename T >

bool Botan::TLS::Extensions::has ( ) const

inline

Definition at line 852 of file tls_extensions.h.

         {
         return get<T>() != nullptr;
         }

Referenced by add(), and deserialize().

has() [2/2]

bool Botan::TLS::Extensions::has ( Extension_Code  type ) const

inline

Definition at line 857 of file tls_extensions.h.

         {
         return get(type) != nullptr;
         }

operator=()

Extensions & Botan::TLS::Extensions::operator= ( Extensions &&  )

default

remove_extension()

bool Botan::TLS::Extensions::remove_extension ( Extension_Code  type )

inline

Remove an extension from this extensions object, if it exists. Returns true if the extension existed (and thus is now removed), otherwise false (the extension wasn't set in the first place).

Note: not used internally, might be used in Callbacks::tls_modify_extensions()

Definition at line 940 of file tls_extensions.h.

         {
         return take(type) != nullptr;
         }

serialize()

std::vector< uint8_t > Botan::TLS::Extensions::serialize

(

Connection_Side

whoami

)

const

Definition at line 193 of file tls_extensions.cpp.

   {
   std::vector<uint8_t> buf(2); // 2 bytes for length field
 
   for(const auto& extn : m_extensions)
      {
      if(extn->empty())
         continue;
 
      const uint16_t extn_code = static_cast<uint16_t>(extn->type());
 
      const std::vector<uint8_t> extn_val = extn->serialize(whoami);
 
      buf.push_back(get_byte<0>(extn_code));
      buf.push_back(get_byte<1>(extn_code));
 
      buf.push_back(get_byte<0>(static_cast<uint16_t>(extn_val.size())));
      buf.push_back(get_byte<1>(static_cast<uint16_t>(extn_val.size())));
 
      buf += extn_val;
      }
 
   const uint16_t extn_size = static_cast<uint16_t>(buf.size() - 2);
 
   buf[0] = get_byte<0>(extn_size);
   buf[1] = get_byte<1>(extn_size);
 
   // avoid sending a completely empty extensions block
   if(buf.size() == 2)
      return std::vector<uint8_t>();
 
   return buf;
   }

size()

size_t Botan::TLS::Extensions::size ( ) const

inline

Definition at line 862 of file tls_extensions.h.

         {
         return m_extensions.size();
         }

take() [1/2]

template<typename T >

decltype(auto) Botan::TLS::Extensions::take ( )

inline

Take the extension with the given type out of the extensions list. Returns a nullptr if the extension didn't exist.

Definition at line 913 of file tls_extensions.h.

         {
         std::unique_ptr<T> out_ptr;
 
         auto ext = take(T::static_type());
         if (ext != nullptr) {
            out_ptr.reset(dynamic_cast<T*>(ext.get()));
            BOTAN_ASSERT_NOMSG(out_ptr != nullptr);
            ext.release();
         }
 
         return out_ptr;
         }

References BOTAN_ASSERT_NOMSG, and T.

take() [2/2]

std::unique_ptr< Extension > Botan::TLS::Extensions::take

(

Extension_Code

type

)

Take the extension with the given type out of the extensions list. Returns a nullptr if the extension didn't exist.

Definition at line 176 of file tls_extensions.cpp.

   {
   const auto i = std::find_if(m_extensions.begin(), m_extensions.end(),
                               [type](const auto &ext) {
                                  return ext->type() == type;
                               });
 
   std::unique_ptr<Extension> result;
   if (i != m_extensions.end())
      {
      std::swap(result, *i);
      m_extensions.erase(i);
      }
 
   return result;
   }

---

The documentation for this class was generated from the following files:

• src/lib/tls/tls_extensions.h
• src/lib/tls/tls_extensions.cpp